A radio communications receiver can sustain interference to some degree. If the power of the interference exceeds the processing gain of the system, additional interference suppression is needed.
The performance of the traditional FFT-based (Fast Fourier Transform) exciser is adequate against stationary interference, i.e. such interference whose frequency contents do not change over an observation interval.
For other types of interference another transform might be more suitable. Several types of interference suppression methods have been investigated in different interfering environments. The problem is how to choose either in advance or adaptively the most efficient interference suppression for the interference type present in a channel.
A general solution for interference suppression is the Recursive Least Squares (RLS) adaptive filter. The problem of using the RLS filter is the computational complexity, numerical properties in fixed-point implementation and initialization.
Bank-type solutions have also been presented in the literature. For every interference suppression method included in the bank the interference suppression is performed completely including the inverse transform, and the best method is chosen based on some criterion, for example signal-to-interference-plus-noise ratio (SINR). Bank-type solutions therefore include lots of excessive computation.